At 18, he has now become the youngest Indian boxer to secure an Olympic berth, surpassing the 19-year-old L. Devendro Singh, who made the cut for the July-August Games last year. Debendra Singh competed as a 19-year-old in the 1996 edition at Atlanta.

Shimizu had a notable height difference and took complete advantage of it in the first round. The Indian who, had to defend more and work on counter attack, was able to get in a few good hits, just before the close of the opening three minutes of play. Shiva was still down a one point deficit (6:7) at the end.

In the second round though, Shiva shifted gears and settled into a good rhythm; he negated the Japanese boxer’s height leverage with some great infighting - the right hand counter punch over the top, worked like a charm for him.

Shiva, 2010 Youth Olympics silver medallist, also threw in a series of left right combinations that yielded fine results. By now Shiva had taken complete control of the bout with a ten point lead (22:12). In the final round he eased off the throttle, but was still able to penetrate Shimizu’s defence at will. The Assam lad went on to win the bout with a total score of 31:17.

Shiva s now assured of at least a silver medal finish from the tournament. In the title clash of the 56 kilogram weight, Thapa takes on Asian Games bronze medallist Wessam Salamana of Syria, Thursday.

India coach G.S.Sandhu hailed Shiva's performance. "Shiva has shown a lot of grit to achieve the Olympic qualification. He was determined to make the cut and the way he went about his business, has been exceptional. He has exhibited great understanding of the game; his maturity coupled with his talent makes him a brilliant future prospect," said Sandhu.

Meanwhile, 2008 Beijing Olympics bronze-medallist Vijender Singh (75kg), suffered a 7:10 loss at the hands of Nursaat Pazziyev from Turkmenistan in the semi-finals while 2010 Asian Games silver medallist Manpreet Singh (91kg) London hopes were over after he was beaten by Asian Games bronze medallist Ali Mazaheri of Iran.

Vijender, however, had already booked his London ticket by winning the quarterfinal bout. Both the Indian boxers will have to be content with a bronze medal finish from the tournament.

Vijender was on the back-foot from the start and trailing 2-3 by the end of the opening round. The 26 year old Indian, with his long reaching arms, tried hard, but was unsuccessful in penetrating the close defence of Pazziyev.

Pazziyev on the other hand counter attacked with success and managed to squeeze in a point each, after the first and the second round (4:6). In the third round, story remained the same with both boxers sticking to the strategy. In the end Vijender, the Asian Games gold medallist, lost the round (3:4) and the bout on points (7:10). The former world No.1, earlier in the competition, defeated 2011 Asian Championship silver medallist Chuluuntumur Tumurkhyag of Mongolia in the quarter-finals to win the all important Olympic quota.

Manpreet too found it difficult to get through the defence of Mazaheri. Although, Manpreet was leading with one point after the first round (3:2), the 30-year-old Iranian, a former Asian Champion, came back strongly in the second and third to take the game away from the Indian. Devendro Singh (49kg), Jai Bhagwan (60kg), Manoj Kumar (64kg) and Vikas Krishan (69kg) have also qualified for the Olympics.